Gas turbine having means for cooling the stator



Nov. 5, 1957 M. LEDINEGG 7 GAS TURBINE HAVING MEANS FOR COOLING THE STATOR Filed April 26, 1951 m1 Fig.2

Uite Sttes Patent GAS TURBINE HAVING MEANS non run srAroR Application April 26, 1951, Serial No. 222,979 Claims priority, application Austria May 2, 1950 4 Claims. (Cl. 25339.1)

COOLING This invention relates to a gas turbine having means for cooling the stator and the inlet guide of the turbine. In the invented structure, air, gas or liquids may be used as a cooling medium. According to the invention the cooling medium first flows in an axial direction through the rotor, the heat absorbed by the blades being transferred to the cooling medium. Subsequently the cooling medium flows along the stator to conduct away the waste gases, and thereafter approaches the stator blades, through which it flows in parallel paths. The stator blades are hollow and each contain a tube, e. g., in their interior. For instance, the stator blades may be traversed by the cooling medium from the outside to the inside and the cooling medium may be conducted away through the tubes located in the blades. Subsequently the cooling medium enters an annular space, whence it is conducted away.

According to the invention the stator blades are pressed from the outside into correspondingly shaped holes in the casing. The pressure difference prevailing between the cooling medium side and the combustion gas side assists in providing a seal.

The structure according to the invention is shown by way of example in Figs. 1 to of the accompanying drawings.

Fig. 1 is a longitudinal partly sectional view of the turbine.

Figs. 2 and 3 are fragmentary partly sectional views at right angles to each other, showing on a larger scale the construction of the stator blades.

Figs. 4 and 5 are sectional views taken through the blades along the lines 4-4 and 5-5, respectively, of Fig. 2.

In Fig. 1, 1 is the rotor turnably supported, for rotation about a common axis, in a stator 30, the rotor being axially traversed by a cooling medium through a passage 31 formed in said rotor and extending therethrough so that the coolers 3 of the rotor blades 4 can deliver their heat to the cooling medium. At 5 the cooling medium emerges from the rotor passage into the passage portion or space 7 between the casing or inner wall 14 and the shell or outer wall 6 surrounding the waste gas conducting portion of the casing 14 of a stator generally designated 30, and finally enters the inner annular chamber portion 8 said space 7 constituting an annular chamber in said stator. From this chamber portion the cooling medium flows at 9 into the hollow stator blades 10 (Fig. 2). At 11 the cooling medium emerges out of the stator blade and enters the outer annular chamber portion 12, out of which the cooling medium is conducted away through the branch 13. The means for guiding the cooling medium from said rotor passage to finally reach the outer annular chamber portion is generally designated guide means. The exhaust branch of casing 14 of the turbine is provided on its inside with a lining 15 of a material of poor thermal conductivity. This lining may also consist of sheet metal, which is fixed to 14 with a small spacing 2,812,156 Patented Nov. 5, 1957 between them. In this manner 14 is cooled so that appreciable differential expansion as compared with the rotor is prevented and smallest distances of play can be maintained.

The blades 1% of the stator are inserted from the outside into openings of the stator which have a corresponding slight taper. This can be seen from Figs. 2 and 3. The first step consists in mounting the blades 10 by pressing them into the annular cones 16. Now the inner tubes or tubular means 21 may be inserted, spacing wings 24 facilitating the guidance and small feet 25 providing a proper spacing from the bottom. It is seen that each tube 21 has opposite open ends, is spaced inwardly from the side wall of blade 10, extends through the outer open end thereof, and is spaced'by feet 25 in part from the closed end of blade 10 which is adjacent the rotor. Subsequently the intermediate wall 17 is mounted and thereafter the nipples 18 are fitted, which conduct the cooling medium through the conical connecting piece 19 to 11. The outer wall 20 is fitted last. The section taken along the line 4-4 of Fig. 2 shows in Fig. 4 the nipple 18 and, in an elevation, the blade cone 16. For instance, the cone and the blade may be welded to each other at 22 (Fig. 2). According to the invention the cone may also be secured to the stator by tightly welding it at 23 around its periphery. The sectional view taken along the line 5-'5 of Fig. 2 shows in Fig. 5 the blade 10 and the tubular means or discharge pipe 21 guided in said blade.

It will be seen from the above description that the space 7 provides a free annular space communicating with the interior of all of the hollow stator blades 10 as well as with the rotor passage, while the wall 17 forms with Wall 20 the chamber 12 which is entirely separated by wall 17 from the free annular space 7. The inner wall of the stator, to which the cones 16 are fixed, and the outer -wall 20 define between themselves an annular chamber divided by the intermediate wall portion 17, which is fixed at its side edges to the outer wall 20, into an inner chamber 8 and an outer chamber portion 12. The several tubular elements 18 and 21 provide a tubular means causing the cooling medium to flow downwardly into blades 10 and from the latter through the tubular means into the outer chamber portion 12.

If air is used as a cooling medium, the invention described enables the cooling of the inlet guide without losses because this air may be utilized as air for combustion. Thus the heat carried oif by the cooling means is utilized in the process. By the installation of the guide blade as described, an arrangement ensuring'safe operation is achieved. At the same time the cooling of the stator blades also cools the stator so that the stator and the rotor can be constructed with smallest distances of play.

What I claim is:

1. A turbine comprising, in combination, a rotor formed with a passage extending therethrough and having a central turning axis, said rotor passage being adapted to have a cooling medium flowing therethrough; a stator coaxial with and surrounding said rotor, turnably supporting the same for rotation about said axis, and having a plurality of hollow stator blades mounted thereon, said blades each including an elongated tubular wall having a closed inner end adjacent said rotor and an open outer end distant from said rotor; and guide means forming part of the stator, communicating with one end of said rotor passage to receive a cooling medium therefrom and communicating with the interior of said hollow stator blades so as to cool the latter with the same cooling medium which fiows through said rotor passage, said guide means comprising a passage portion having an inner annular chamber portion communicating with the interior of all of said hollow stator blades and communicating with said rotor passage to receive the cooling medium therefrom, an outer annular chamber portion entirely separated from said inner annular chamber portion by an intermediate annular wall portion defining the outer limit of said inner annular chamber portion and being located around a part of said passage portion, and a plurality of tubular means extending from said intermediate wall portion into the interior of said hollow blades, respectively, through said open ends thereof, and being spaced inwardly from the side walls of said blades and at least in part from said closed ends of said blades, said plurality of tubular means each having opposite open ends so that said cooling medium flows in parallel from said free annular space along the outside of said tubular means into said hollow stator blades and through said plurality of tubular means into said outer annular chamber.

2. In a turbine, in combination, a stator having an inner wall located around a predetermined axis and an outer wall spaced from said inner wall to form an annular chamber in said stator; an intermediate wall portion fixed to said stator and being located between said inner and outer walls to form an inner annular chamber portion with said inner stator wall and, with said outer stator wall, an outer annular chamber ,portion separate from said inner chamber portion; a plurality of'hollow stator blades fixed to said inner stator wall, having tubular side walls extending therefrom toward said axis, having inner closed ends directed toward said axis, and having opposite free open ends communicating with said inner annular chamber portion; and a plurality of tubular means fixed to said intermediate wall portion and respectively extending into said hollow stator blades and being spaced inwardly from said side walls thereof and at least in part from said closed ends thereof, each of said tubular means having opposite open ends which respectively communicate with the interior of the respective stat-or blade and with said outer annular chamber portion; extending from said intermediate wall portion into the interior of said hollow blades, so that a cooling medium in said inner annular chamber portion flows in parallel into all of said stator blades along the spaces between said plurality of tubular means and said stator blades and through said plurality of tubular means into said outer annular chamber portion.

3. In a turbine, in combination, a stator having an inner wall located around a predetermined axis and an outer wall spaced from said inner wall to form an annular chamber in said stator; an intermediate wall portion fixed along opposite side edges thereof to said outer wall of said statorand being located at all parts except said side edges thereof between and in spaced relation to said inner and outer walls to form an inner annular chamber portion with said inner stator wall and, with said outer stator wall, an outer annular chamber portion separate from said first chamber portion; a plurality of hollow stator blades fixed to said inner stator wall,

4 having tubular side walls extending therefrom toward said axis, having inner closed ends directed toward said axis, and having opposite free open ends communicating with said inner annular chamber portion; and a plurality of tubular means fixed to said intermediate wall portion and respectively extending into said hollow stator blades and being spaced inwardly from said side walls thereof and at least in part from said closed ends thereof, each of said tubular means having opposite open ends which respectively communicate with the interior of the respective stator blade and with said outer annular chamber portion; extending from said intermediate wall portion into the interior of said hollow blades, so that a cooling medium in said inner annular chamber portion flows in parallel into all of said stator blades along the spaces between said plurality of tubular means and said stator blades and through said plurality of tubular means into said outer annular chamber portion.

4. A turbine comprising, in combination, a rotor formed with a passage extending therethrough and having a central turning axis, said rotor passage being adapted to have a cooling medium flowing therethrough; a stator coaxial with and surrounding said rotor turnably supporting the same for rotation about said axis and having a plurality of hollow stator blades mounted thereon, said blades each including an elongated tubular wall having a closed inner end adjacent said rotor and an open outer end distant from said rotor; and guide means forming part of the stator communicating with one end of said rotor passage to receive a cooling medium therefrom and communicating with the interior of said hollow stator blades so as to cool the latter with the same cooling medium which flows through said rotor passage, said guide means comprising a passage portion having an inner annular chamber portion communicating with the interior of all of said hollow stator blades and communicating with said rotor passage to receive the cooling medium therefrom; an outer annular chamber portion entirely separated from said inner annular chamber portion by an intermediate annular wall portion defining the outer limits of said inner annular chamber portion and being located around a part of said passage portion; and means for conducting said cooling medium from said inner annular chamber portion through said hollow stator blades to said outer annular chamber portion.

References Cited in the file of this patent UNITED STATES PATENTS 2,154,481 Vorkauf Apr. 18, 1939 2,540,456 Price Feb. 6, 1951 2,563,269 Price Aug. 7, 1951 FOREIGN PATENTS 346,599 Germany u Jan. 5, 1922 420,781 Germany Oct. 31, 1925 824,013 France Oct. 25, 1937 897,034 France Mar. I5, 1944 

